Rotary engine and pump



May 12, 1931.

J, DAP

ROTARY ENGINE AND PUMP Filed May 26, 1927 4 Sheets-Sheet l I May 12, 1931. J. DAP

ROTARY ENGINE AND PUMP Filed May 26, 1927 4 Sheeis-Sheet 2 A /F V//////////// 4 Sheets-Sheet 3 J. DAP

May 12, 1931.

ROTARY ENGINE AND gum Filed May 26, 1927 y 12, 1931? J. DAP

ROTARY ENGINE AND PUMP Filed May 26, 1927 4 Sheets-Sheet 4 lnvenfor: /T"" 7 liar/1y I to Patented May 12, 1931 r eerie 1:.

. ATE

.J'EAN DAP, F PUTEAUX, FRANCE, ASSIGNOR TO DAF-IVIOTOR-PATENT-GESELLSGHAFT I M. B. H., 0 CGLGGNE-HOLWEIDE, GERMANY j ROTARY ENGINE AND PUMP Application filed May 26, 1?:27, Serial N'o.=19l,460, and in Germany July- 3, 1926.

This invention relates to the class of engine having a group of circumferentially arranged cylinders and a group of appertaining pistons,

one of said groups rotating continuously and 6 the other intermittently, being alternately relatively held back and accelerated forward. Such engines unite in themselves all the advantages of'rotary engines, in particular that of direct transmissionof the power toor from a rotating power shaft, with the advantages of the usual cylinder and crank shaft engine. The basic class or type is usable not only for power engines but also for working machines which are inversions of power engines, for example pumps and compressors.

The essential conditions for practical operation of such a machine are the following: The working force must be transmitted in tangential direction, directly to the driving shaft. The movement of the intermittently rotating group, for example the pistons must be so controlled that the pistons alternately during one stroke remain stationary and during the next stroke move through if a is the distance moved through during one stroke, i. e. half the piston movement, by the uniformly rotating cylinders. The mechanism which controls the piston movement must not take part in the transmission of power, since otherwise purely tangential transmission of the power is not possible. The pistons during their stationary period, that is during the power stroke, must be locked against movement in either direction.

This locking must be absolute, that is it must be derived from the stationary partof'the machine. Locking of the pistons in relation to the cylinders as hitherto proposed is naturally insufficient, since then during the power them back just as much as on the cylinders to drive them forward. The pistons in their movement must be accelerated or retarded in a continuous manner. The movement must not start suddenly from rest or stop suddenly. In practically all hitherto known constructions of such motors the piston movement commences suddenly from rest with the full speed of the cylinders, or ends suddenly therewith. Practically however there is no mateing arrangement and stroke the force acts on the pistons to drive rial which will stand the shocks ofsuch action. The movement'of the pistons must be controllable to follow closely some speed curve known to be the optimum.

The present invention has for its object a machine satisfying all the essential conditions and consists in the combinations described below and pointed out in the claims.

In this motor the piston movement positively follows a-speed curve known to be the optimum; it is not however bound to one particular curve, but can be arranged to follow any suitable curve. The pistons during their stationary period are locked against both directions of rotation, and not just relatively to the cylinders but absolutely to the stationary part of the machine.

An internal combustion engine in accordance with the invention is illustrated by way of example in the accompanying drawings.

The upper half of Figure 1 is a section on the line IT of Figure 2. The lower half of Figure 1 is an elevation on the line Ta-Ia of Figure 2. The upper half of Figure 2 is a section on the line IT-ITITTI of Figure 1. The lower half of Figure 2 is a section on the line IIIIa of Figure 1.

Figure 3 is a section on the line IIIIII of Figure 9.

Figiire 4 is a section on the line IV-IV of Figure 9. 7 Y c Figure 5 is a speed diagram.

Figure 6 is a diagram showing the path of the pin 13.

Figure 7 shows an alternative connecting arrangement.

Figure 8 shows another alternative connect- Figures 9 and lO are respectively front views and sectional plan on line XX of Figure 9v of the head end of the connecting rod shown in Figure 1, shown on an enlarged scale.

In Figure 5 of the accompanying drawings the piston velocity is illustrated in graph form. The interval 28 represents the path of the pistons between the commencement of the first and second movement cycle and so forth. I The half value of this interval is then s and l may betermed the stroke of the machine, analogous to the stroke in an ordinary crank motor. During all strokes s the cylinders rotate with substantially uniform speed '0. The piston speed must then be 0 during the first stroke, while in the second stroke the speed must proceed from 0 through a maximum to 0 again. The course of this speed curve is so regulated that the piston during the pe .riod the cylinder traverses onestroke .9 covers the full interval 28. In other words, after afull motion cycle the pistons will again occupy the same positions relative to the cylinders. In this way smooth operation of the machine is achieved and furthermore it is technically possible to construct the machine from the point of view ofmaterials. All other constructions of the same basic idea fail on thequestion of materials. In order now to enable the expansion energy in the cylinder to be used tangentially, there must not be any power transmitting connection between the pistons and cylinders during the working stroke. The back pressure on the pistons must therefore be taken by the stationary part of the machine. A look must therefore be provided between the pistons and stationary part of the machine, which on one hand prevents rotation of the pistons in the .opposite direction to the cylinders during the power stroke, and on the other hand does not allow the pistons to move in the direction of the cylinders under the action of the vacuum during the suction stroke. In other words, the locking must act in both directions of rotation. Advantageously the pistons are always locked against rotation opposite to the rotation of the engine and in addition during every alternate stroke against rotation in the same direction as the engine.

In the stationary part 3 of the engine is borne a shaft 4, on which a disc 1 to which the cylinders are rigidly connected, is keyed. In-

stead of the two cylinders shown, any desired number can be used.

A piston carrier 2- to which the pistons are rigidly connected is rotatably borne in relation to the cylinder disc 1. The cylinder disc 1 carries. on one end of its hub a cam 7 concentric with which is a cam 8 on the piston carrierQ, On the cam surfaces 7 and 8 slide the two ends of a lock lever 6, which is pivoted at the centre on a bolt 5 secured to the stationary part 3 of the engine. The cam curve I comprises a recessed part 7?) and a raisedpart 7a concentric with the axis of the machine, for each double stroke, while the .cam curve 8 .comprises a long tooth for each pair of parts 7?) and 7a on the curve 7. When the part 7a of the .cam curve 7 is sliding on the endof the lever 6, the other. end of the'lever. clearly locks the tooth of'the curve 8 against counter-clockwiserotation. It also locks the curve-againstrotation in the clock- .wise directi'onisince owing tot-he increasing period just having commenced in Figure 1.

During the previous stroke interval the curve 7 has moved through an angle aand the curve 8 through an angle 2a. The hollow part 7 b of the curve 7 is shaped so that the ends of the lever contact with both curves when both curves are moving. The curve 7 runs steadily and continuously while the curve 8 runs intermittently as explained above, under the,

action of a suitable mechanism describedin detail below. Considering now the forces which act in the position shown in Figure 1 and during the succeeding stroke when the curve 8 must be locked in both directions. If

the curve 8 tends to move in the direction of rotation of the engine,i. e. counter clockwise, the lever tends to rotate counter-clockwise on its pivot 5, which is resisted by the circular part of the curve 7 and the pivot 5. Conse-- quently the curve '8 cannot move in counterclockwise direction. If the curve tends to move in the opposite direction to the engine, i. e. clockwise, as occurs during the suction stroke, this will be resisted by'jambing of the curve 8 against the end ofthe lever, since the curve 8 slopes in toward the-centre, and therefore such motion cannot take place as long as the materials hold. The motion is further resisted by friction which in itself is slight,

but whichtends to rotate the lever 6 clockwise which increases the jambing action. Vhen both curves are moving, forces, in a direction counter to therotation of the engine do not normally occur, owing to the action of the v mechanism connecting the .piston and cylinder groups. If such a force did arise it would be resisted just asinthe position shown in Figure 1 by the inward slope of. the curve 8 and the tendency to turn the lever 6 clockwise by the-friction on the lever. During the stationary period of the pistons:t h e operating mechanism between the pistons and cylinders, as shown below, is out of action. Itis clear therefore that all the forcesacting on the piston are taken by the fixed part-3 of the engine. As can be seen fromthe speed diagram, Figure 5, the lock lever 6 does not serve tobrake-the speed of the pistons, since at the instant in question the pistons. have no speed. The purpose of the lock lever 6 is solelythe locking of thestationary pistons against both directions of rotation. Only .when the lock lever 6 reaches the recessed parts of the curve-7 is the locking by curve .8 against rotation. in the samedirection'as the engine released, andithe pistonscan then move accordmgto thespeed curve of Figure under the actuation ofthe -mecha-- nismbetween the cylinders and pistons.

The epicycloid gear shown as an' example, of which the connecting rod length is positively variable, is used as a mechanism satistying the aforementioned conditions;- The connecting rod pin. 13 connected with the :cylinder disodescribes' the curve shown in Figure 6. This path Consists of two portions of equal timelength, the arcs 29 to 33. and the I loops 29-.3029 (or 33'3433) During ment that the pistons remain-stationary cannot'be fulfilled without further provision since the path proceeds backwards and forwards over a short distance and does not in itselfrepresent a stationary periodav It is therefore necessary to provide a device which compensates for the movements in question.

The action of the device illustrated by way of example is'explained as follows:

On the'stationary'part 3 of the *machineis a toothed crown 9 on which rollsa pinion 10.

.This pinion .is fast on the spindle'll of a crank shaft borne by the cylinder disc 1. By means of a web 12 the rotation of the pinion is transmitted to the pin 13 which then describes the path shown in Figure 6. The piston body 2 carrries a-pin20. These two pins 13and are coupled by a connecting rod 14 of which oneend is borne on the pin 13, and of which the other end carries the compensating devicev for varying its length. Forthis purpose the other end of the connecting rod 1 L surrounds thepin 20 frame fashion. In the opening '17 of this. frame a small cross head 19 which'surrounds'the pin 20, can slide in either direction. Over the frame form opening 17 extend two'bars 15 secured to or formed integral with the rod 1 1. In the centre of these bars 15 is borne on a pin 21 a toothed wheel 18 provided with a lever arm 18. To the left and right of the cross head 19, within the frame 17 and borne between the bars 15 are two eccentrics 16, to which toothed wheels 22 are secured. The two toothed wheels 22 mesh with the toothed wheel 18. The free end of the lever 18 on the wheel 18" is articulated to a rod 23 which is guided in the rotatable guide 24 mounted uponthe piston body 2. The free end 27 of the rod 23 operates in a cam groove 26. This curve 26 is cut in a projection 25 secured or formed upon the rod 14. The curve 26 is so formed that the rod 1 L has its normal length -when the point '13 is describing the parts 31-32 of the path in Figure 6,.the cross head 19, being so controlled by the eccentrics 16 however, that the changes in lengthnecessitated by the passage over the loops are al ways produced The changes in length of theconhecting rod already begin at 28 (or 32) andend at 31 (or' While immobilization of theipoint 20 is produced in this 'way, during the-sections 28+29; 29-31;

32-.33; 33-35; thespeed is respectively reduced to 0 or raised from 0. I r Another simple arrangement for controlling the piston movement is shown by way of' example in Figure7 of the accompanying drawings. The pistons 40 are moved .forward by a rod 41- which is pivoted to the pistons at 42. The end point 43 ofthis .rod

moves (1) by'sliding on the crank arm 44,

the movement of whichis 1 derived in any suitable way from the movement of the engine, (2) on the curved path 45 which is rigid with the cylinders and-is so formed that the pistons receive exactly the above described movement.

Another arrangement of themechanism for controlling the piston movement is diagrammatically shown inFigure 8 of the accompanying drawings. The point 42 on the pistons is guided in the, curve a5 which rotates rigidly with the toothed wheel 48, the

prescribed motion being produced by suitably forming the curve 45.; With thisarrangement, by suitably forming the curve,

the speedfcurve can be given any desired form, for-exampleit can be made parabolic or the like. The comparatively large curve is formed in a disc47, which can at the same 7 time serveas a flywheel. 1 I

What I claim is 4 1.*In a machine of the class described,

means for locking the intermittently rotating group both ways during its stationary period to the'stationary :part of the machine, and

positively controlled 'mechanism separate from the mechanism transmitting the power forces connecting the two; groups adapted to hold said intermittently rotating group still during its stationary'periodjand to forward said intermittently rotatinggronp with a mean speed of twice themachine speed without shocks -at: the. commencement and finish during the moving periods of said group'bothways during its stationary period to the stationary part of the machine, mechanism operated I by the continuously rotating'group including a pin. describing an epicycloidal path, a coupling rod connecting saidpin and said intermittently:rotating group, and positively controlled means for automatically varying the length of said r'od so that said intermittently moving groupis zheld still and forwarded withoutshock-atthe appropriate times. 1

3.1In a machine of the class described,

-- means rfor "locking the intermittently rotat- -of sai'd rodpivoted to saidintermittently rotating group, and cam means :for automatically sliding said crosshead so that said intermittently moving-group is held still and .jforwarded without-shock at the appropriate times. v

4. In a -machine of the class described,

means for locking the intermittently rotating group during its stationary period to the stationary part of the machine, mechanism operated by the continuously rotating group including a pin describing an epicycloidal path, a coupling ro'd pivoted at one end to said-pin, a cross head sliding in the otherend of said rod pivoted to said intermittently rotati-ng group, an eccentric borne in said rod on each si'deof and contacting with said cross head, means including an arm for rotating said eccentrics, a cam borneon said rod and aconnectin-g member pivotally and sli'dably 'borne on said'intermittently rotating group coupled to said arm and operatively connected withsaid-cam.

5. Ina machine of theola ss described, a concentric-cam path on the continuously rotating group, a second concentric cam path on theintermittently rotating group, a lock --member pivoted to the stationary part of the machine co-acting Withsai'd cam paths to lock said intermittently rotating group both ways to said stationary part of the machine during its stationary periods and positively controlled mechanism separate from the mechanism transmitting the power forces connect- ,ingthe two groups adapted to holdsaid intermittentlyrotating group still during its :stat-i'onary period and to forward said-intermittently rotating group with a mean speed of twice the machine speed without shocks at'thecommencementand finish during the moving periods of said-group.

6. In'a machine of the class described, a concentric cam pathon'the continuouslyrotating group, a second concentric cam path 'ont'he intermittently rotating group, alock member pivotedto the stationary part of the machine co-acting with said cam paths to lock said intermittent ly rotating group to said 'sta'tionarypart of the machine during its sta tionary periods against rotation in either direction and against rearward rotation during its moving periods, and positivelycontrolled mechanismseparate fromthe mechani-sm transmitting the power forces-connect- -ing the two groups a dapted to hold said in- =termittently rotating group still during its stationary period and to forward said intermittent-ly rotating group with a mean speed of twice the machlneispeed without shocks at the commencement and finish during the mov-' its stationary periods against rotation in either'direction and against rearward rotation during its moving periods, mechanism operated bysaid continuously rotating group including apin describing an epicycloidal path, a coupling rod connecting said pin and said intermittently rotating groups, andpositively controlled means for automatically varying the length of said rod so that said intermittently moving group is held still and forwarded without shock at the appropriate times.

8. Ina machine of the class described, a concentric cam path on the continuously rotating group, a second concentric cam path on theintermittently rotating group, a lock member pivoted to the stationary path of the machine co-acting with said cam paths to locksaidintermittently rotating group to said stationary part'of the machine during its stationary periods against rotation in either direction and against rearward rota tion during its moving periods, a toothed crown on said stationary part, a pinion borne by said continuously rotating group meshing with said crown, a crank pin rotated by said pinion, a coupling rod connecting said pin and-said intermittently rotating groups, and positively controlled means forv automatically varying the length of said rod sothat said'intermittently moving group is held still and forwarded without shock at the appropriate times.

In testimony whereof I have signed my name to this specification.

' JEAN DAP. 

